Why does our body reject other people’s donated organs and require immunosuppressants to be taken but getting someone else’s blood is ok?

Question

Why does our body reject other people’s donated organs and require immunosuppressants to be taken but getting someone else’s blood is ok?

In: 157

Answer 1

Finally my years of training as a carbohydrate chemist come into play!

Basically, your cells all have a number of small but complex sugar chains on their surface. Your body learns early in development to recognize this pattern to be “self” and anything else to be “other” which needs to be removed. On blood cells, specifically red blood cells, there is a much more limited diversity of sugar chains, which give rise to the blood groups most people are familiar with. But on other tissues the structures are more complex. Basically, it much easier to trick your body into thinking blood is “self” than for a complete organ.